Conventional systems, such as the global positioning service (GPS) and global navigation satellite service (GLONASS) can determine the geographic location of a device that is compatable with one of these systems. These conventional systems are complex, such as GPS systems, which require satellites. GPS receivers require a view of a sufficient number of the GPS satellites to keep the horizontal dilution of precision (HDOP) to a modestly low value. There are numerous instances for which these complex systems may fail to provide the desired geolocation services. Particularly, in urban areas, a GPS receiver may not be capable of receiving signals from GPS satellites due to one or more dielectric canyons formed by streets and/or the structural shielding of large metallic members.
In view of the above discussion, there remains a need in the art for geographic location systems that provide a cost-effective service within urban and other similarly shaded areas that can function properly where GPS and other systems are hampered because of the urban nature of the surroundings.